<!DOCTYPE HTML>
<html>
<head>
<meta content="text/html; charset=UTF-8" http-equiv="content-type"/>
<title>HTML5 Drag and drop demonstration</title>
<style type="text/css">
#boxA, #boxB, #boxC { 
  float:left; width:200px; height:200px; padding:10px; margin:10px;
}

#boxA { background-color: blue; }
#boxB { background-color: green; }
#boxC { background-color: yellow; }

#drag, #drag2, #drag3 {
  width:50px; height:50px; padding:5px; margin:5px;
  -moz-user-select:none;
}
#drag { background-color: red;}
#drag2 { background-color: orange;}
#drag3 { background-color: purple; border:3px brown solid;}

</style>
<script type="text/javascript">
function dragStart(ev) {
    ev.dataTransfer.effectAllowed='move';
    //ev.dataTransfer.dropEffect='move';
    ev.dataTransfer.setData("Text", ev.target.getAttribute('id'));
    ev.dataTransfer.setDragImage(ev.target,0,0);
    return true;
}

function dragEnd(ev) {
    ev.dataTransfer.clearData("Text");
    return true
}


function dragEnter(ev) {
    var idelt = ev.dataTransfer.getData("Text");
    return true;
}

function dragOver(ev) {
    var idelt = ev.dataTransfer.getData("Text");
    var id = ev.target.getAttribute('id');
    
    return false;
    
    if( (id =='boxB' || id =='boxA') && (idelt == 'drag' || idelt=='drag2'))
        return false;
    else if( id =='boxC' && idelt == 'drag3')
        return false;
    else
        return true;
}

function dragDrop(ev) {
  console.log('drop');
    var idelt = ev.dataTransfer.getData("Text");
    ev.target.appendChild(document.getElementById(idelt));
    ev.stopPropagation();
    return false; // return false so the event will not be propagated to the browser
}

</script>
</head>
<body>
    <h1>Drag and drop demo in a HTML document, using the HTML5 drag and drop API</h1>
    <div> The red box and the orange box can be dragged and dropped between 
    the blue and the green boxes.
    The purple box can be dragged and dropped only to the yellow box.
    </div>

    <div id="boxA"
        ondragenter="return dragEnter(event)"
        ondrop="return dragDrop(event)"
        ondragover="return dragOver(event)">

      <div id="drag" draggable="true"
            ondragstart="return dragStart(event)"
            ondragend="return dragEnd(event)">drag me</div>

      <div id="drag2" draggable="true"
            ondragstart="return dragStart(event)"
            ondragend="return dragEnd(event)">drag me</div>

      <div id="drag3" draggable="true"
            ondragstart="return dragStart(event)"
            ondragend="return dragEnd(event)">drag me</div>

    </div>

    <div id="boxB"
        ondragenter="return dragEnter(event)"
        ondrop="return dragDrop(event)"
        ondragover="return dragOver(event)">
    </div>

    <div id="boxC"
        ondragenter="return dragEnter(event)"
        ondrop="return dragDrop(event)"
        ondragover="return dragOver(event)">
    </div>
    <div style="clear:both">Example created by <a href="http://ljouanneau.com/blog/">Laurent Jouanneau</a>.</div>
    <script>
    var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
    document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
    </script>
    <script>
    try {
    var pageTracker = _gat._getTracker("UA-1656750-18");
    pageTracker._trackPageview();
    } catch(err) {}</script>
</body>
</html>